Situational power is what men rely on to get away with things like this.
There's a big difference between a greeting kiss on the cheek, and a kiss on the lips. He held her head to remove her chance of turning her face at the last second. Not OK.
Her immediate reaction was a nervous smile and laughter. Very common. Her 5 minutes later reaction was saying that the kiss was unwanted and that she didn't like it. Her 1 hr later "reaction" was the official statement.